<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onMounted, onUnmounted, ref } from 'vue';
// 不要在组件内部获取数据渲染
// vue3
// defineProps({
//   slides : {
//     type : Array,
//     required : true
//   }
// })

// vue3+ts
const {slides, autoplay = false, duration = 2000} = defineProps<{
  slides: BannerItem[],
  autoplay?: boolean
  duration?: number
}>()
const active = ref(0)
// 点击上一张函数
const prev = ()  => {
  if(active.value === 0) {
    active.value = slides.length - 1
  }  else {
    active.value--
  }
}
// 点击下一张函数
const next = ()  => {
  if(active.value === slides.length-1) {
    active.value = 0
  }  else {
    active.value++
  }
}


// 自动轮播
// 注意1 : 当组件挂载完毕后,再开启定时器
// 注意2 : setInterval是node中的setInterval,要想是window下的setInterval,就要写window.setInterval
let timer:number = -1

onMounted(() => {
  // timer =  window.setInterval(() => {
  //   // console.log("开启定时器")
  //   next()
  // },3000)
  start()
})

onUnmounted(() => {
  // clearInterval(timer)
  stop()
})

const stop = () => {
  clearInterval(timer)
}

const start = () => {
  // autoplay为ture时,就开启定时器,自动轮播
  // autoplay为false时,就不开启定时器,不自动轮播
  if(!autoplay)  return
  timer =  window.setInterval(() => {
    // console.log("开启定时器")
    next()
  },duration)
}
</script>

<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="start">
    <!--轮播图图片-->
    <ul class="carousel-body">
      <li class="carousel-item" v-for="(item, index) in slides" :key="item.id" :class="{ fade: active === index }">
        <RouterLink :to="item.hrefUrl">
          <img :src="item.imgUrl" alt="" />
        </RouterLink>
      </li>
    </ul>
    <!--上一张-->
    <a href="javascript:;" class="carousel-btn prev" @click="prev"><i class="iconfont icon-angle-left"></i></a>
    <!--下一张-->
    <a href="javascript:;" class="carousel-btn next" @click="next"><i class="iconfont icon-angle-right"></i></a>
    <div class="carousel-indicator">
      <!--// 点击小圆点切换-->
      <span v-for="(item, index) in slides" :key="item.id" :class="{ active:active === index }"
        @mouseenter="active = index"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;

  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }

    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;

      &.fade {
        opacity: 1;
        z-index: 1;
      }

      img {
        width: 100%;
        height: 100%;
      }
    }

    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;

      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;

        ~span {
          margin-left: 12px;
        }

        &.active {
          background: #fff;
        }
      }
    }

    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;

      &.prev {
        left: 20px;
      }

      &.next {
        right: 20px;
      }
    }
  }

  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>